1. Field of the Invention
The present invention relates in general to computer implemented processes for improving drilling operations, and in particular to a system and method for facilitating the selection and use of drill bits in order to minimize the negative impact of abrasivity of the earth formation.
2. Description of the Prior Art
Bit abrasion is an undesirable operating condition which impedes drilling operations. In general, drilling operations are performed in a manner which minimizes the possibility of the occurrence of bit abrasion. One factor which can be controlled is the selection of particular drill bits from a group of available drill bits. Certain bits may be less prone to abrasion under certain drilling conditions, while other bits are more prone to abrasion under certain drilling conditions.
It is one objective of the present invention to provide a new system, method, and apparatus for providing an indicator of potential bit abrasion in a particular wellbore, which utilizes an inference engine computer program which consists of executable instructions, and which is adapted to utilize a plurality of wellbore parameters as inputs, including forensic wellbore data, and which includes at least one rule matrix which defines a plurality of fuzzy sets which establish correspondence between the plurality of wellbore parameters and the indicator of potential bit abrasion.
It is another objective of the present invention to provide such an indicator of potential bit performance which provides an indication of the potential for undesirable abrasivity of earth formations.
It is another objective of the present invention to provide an indicator which may be utilized in selecting particular drill bits for use in a particular wellbore.
The foregoing and additional objectives are achieved as follows. A method is provided for generating an indicator of potential bit abrasion in a particular wellbore. Forensic wellbore data is obtained from at least one previously drilled wellbore which is determined to be comparable to the particular target wellbore. Typically, the comparable wellbore comprises an xe2x80x9coffsetxe2x80x9d wellbore which is proximate the target wellbore, and which has similar geologic features. An inference engine computer program is provided which consists of executable program instructions. It is adapted to utilize a plurality of wellbore parameters, including the forensic wellbore data. The inference engine includes at least one rule matrix which defines a plurality of fuzzy sets. These fuzzy sets establish correspondence between the plurality of wellbore parameters and the indictor of potential bit abrasion. The inference engine computer program is loaded onto a data processing system. At least the forensic wellbore data is supplied as an input to the inference engine computer program. The data processing system is utilized to execute the program instructions of the e inference engine computer program. This causes the application of the inputs to the inference engine computer program. The inference engine computer program produces as an output an indication of potential bit abrasion in the particular target wellbore.
The above as well as additional objectives, features, and advantages will become apparent in the following description.